The investigative effort of the Dental Research Department at the Children's Medical Center is directed toward congenital craniofacial malformation. In broadest aspects, this work is seeking to better understand the morphologic consequences of defective development in anticipation that it will lead to greater understanding of both normal and abnormal growth. The work utilizes both clinical and radiologic information and to date has focussed upon Down's anomaly, the Broad-Thumbs/Hallux complex, endemic cretinism and those skeletal syndromes categorically classified as dysostoses with craniofacial involvement. Additional and recent efforts have been directed toward craniostenosis, palatal and lip clefting and facial development in juvenile rheumatoid arthritis. Down's syndrome children are born with decided skull shape and cranial base features that easily distinguish them from non-Down's. While these differences persist they become less and less pronounced with age. There appears to be a strong possibility that skull shape and cranial base morphology are interrelated. In endemic cretinism the dysmorphic pattern of the face and skull is reflected in lack of frontal prominence, reduced nasal bone material and maxillary hypoplasia. The frontal sinus is small and there is a relative prognathism. The craniofacial aberrations of this disease bear little resemblance to that seen in the so-called sporadic cretin. BIBLIOGRAPHIC REFERENCES: Israel, H. 1977 The Dichotomous Pattern of Craniofacial Expansion during Aging. Amer. J. Phys. Anthrop., in press. Israel, H. 1977 Craniofacial Aspects Of Endemic Cretinism. Abstr., American Association for Dental Research, June 23-26, 1977.